Hi Annie. So sorry to hear that you are having this issue with long QT. I had similar issue and even fainted once. I had my heart deliberately stopped by parametics and re-started back in 2015. Mine was diagnosed as superventricular tachycardia. I wonder what the difference is between that and long QT? Anyway, I was never on the Big 3 meds, so those were not behind my heart issue. I also want to add that in all of my reading of case studies involving mac/bronchiectasis; many patients also experience heart issues. It seems to be one of the co-morbid 'sister' ailments that come with lung ailments. I hope you can get your heart straightened out; I know how scary it can be.